Influence of the Assembly State on the Functionality of a Supramolecular Jagged1-Mimicking Peptide Additive

Expanding the bioactivation toolbox of supramolecular materials is of utmost relevance for their broad applicability in regenerative medicines. This study explores the functionality of a peptide mimic of the Notch ligand Jagged1 in a supramolecular system that is based on hydrogen bonding ureido-pyrimidinone (UPy) units. The functionality of the peptide is studied when formulated as an additive in a supramolecular solid material and as a self-assembled system in solution. UPy conjugation of the DSL_JAG1 peptide sequence allows for the supramolecular functionalization of UPy-modified polycaprolactone, an elastomeric material, with UPy-DSL_JAG1. Surface presentation of the UPy-DSL_JAG1 peptide was confirmed by atomic force microscopy and X-ray photoelectron spectroscopy analyses, but no enhancement of Notch activity was detected in cells presenting Notch1 and Notch3 receptors. Nevertheless, a significant increase in Notch-signaling activity was observed when DSL_JAG1 peptides were administered in the soluble form, indicating that the activity of DSL_JAG1 is preserved after UPy functionalization but not after immobilization on a supramolecular solid material. Interestingly, an enhanced activity in solution of the UPy conjugate was detected compared with the unconjugated DSL_JAG1 peptide, suggesting that the self-assembly of supramolecular aggregates in solution ameliorates the functionality of the molecules in a biological context.